1. Field of the Invention
The invention relates to a control system that controls a running characteristic, such as a driving force characteristic and a chassis characteristic, on the basis of a predetermined index obtained on the basis of a running condition, such as the acceleration of a vehicle.
2. Description of Related Art
Driver's expectations and requests to a vehicle are various for each driving scene. Quick running (so-called sporty running) is desired in some driving scenes, and smooth relaxed running (so-called mild running) is desired in other driving scenes on the contrary. Thus, there are various scenes in which vehicles are running. In contrast to this, the running characteristic of each vehicle is predetermined in a design phase on the basis of the type of a vehicle, or the like, and may not completely agree to a driver's driving orientation (or a driver's driving taste).
In an existing art, there have been various attempts to reduce such disagreement between the running characteristic of a vehicle and the driving orientation of a driver as much as possible. For example, Japanese Patent Application Publication No. 06-249007 (JP-A-06-249007) describes a driving force control system that uses a neurocomputer. The driving force control system is configured to learn the correlation of an acceleration against an accelerator stroke and a vehicle speed as a required acceleration model and then compute a throttle opening degree on the basis of a deviation between the required acceleration model and a second reference acceleration model that incorporates a driving orientation and a deviation between the second reference acceleration model and a standard first reference acceleration model.
Vehicles are transportation equipment that consumes energy, such as gasoline, light oil and electricity, to run, so energy efficiency or a fuel efficiency characteristic is desirably excellent. Therefore, it is necessary to develop a technique for achieving both improvement in energy efficiency and improvement in running characteristic.